Book 13, Question 16
Why Do Houseplants Lean Toward a Window?
Plants turn toward light because they use it to make food. A growth chemical in the stem moves to the shaded side, and the shaded cells grow longer. That bends the stem toward the window!
More fun facts
- Plants bend toward light in a growth response called phototropism.
- Indoor plants get much more light on one side, which switches on light sensing molecules mostly on that side.
- A plant on a windowsill gets light mostly from one side, so it leans strongly.
- Trees outdoors respond more to gravity, which keeps them growing upright.
- Responding to gravity is called gravitropism.
Sources: Scientific American, Science News Explores
Questions kids ask
Why don't trees outside lean like houseplants?
Outdoors, light comes from more directions, and the pull of gravity keeps trees growing upright.